Centrifugal Fertilizer Research Articles

Case Study on the Economic and Environmental Impact of the Introduction of the Variable-Rate Distribution of Fertilizer in Wheat (Triticum aestivum L.) Cultivation

Fertilization plays a strategic role in the cultivation of wheat, contributing to harvest yield, both in quantitative and qualitative terms. However, similarly to all farm inputs, it has both economic and environmental impacts due to fertilizer dispersion into the environment during its distribution, as well as any excess fertilizer not used by the crop. Precision agriculture, which introduces the possibility of distributing fertilizer following prescription maps, has an immediate effect on dosage compliance according to the request and potential for use by each homogeneous area of the crop. An experimental field (about 15 hectares) at the Council for Agricultural Research and Economics (CREA) of Treviglio (BG) in Northern Italy was fertilized using a centrifugal fertilizer spreader combined with a tractor, equipped with a satellite system to distribute urea led by prescription maps. The purposes of this research were to verify (i) the effect of fertilization, performed with precision agriculture (PA) criteria at a variable rate; (ii) the comparison of the economic impact of the quantities of fertilizer required by precision agriculture compared to the distribution required in previous years (fertilizers administered according to conventional agriculture). The treated areas showed a significant yield improvement (almost 14%) when fertilization was performed according to the prescription map. With a negligible margin of error of less than 0.001, the total amount of fertilizer used was the same in both years.

Design Optimization and Experimental Verification of Spiral Cone Centrifugal Fertilizer Apparatus Based on the Discrete Element Method

This study attempts to optimize the arc-shaped coned disk affecting the uniformity of the earlier designed fertilizer apparatus (FA), in particular, for application in the rice–oil rotation region in the middle and lower reaches of the Yangtze River, China. Based on theoretical analysis, a circular coned disk with the curvature gradual decline (GD) from top to bottom was designed, and the equation of the circular cone was determined. The EDEM discrete element software was used, using the coefficient of variation of the fertilization amount consistency in every row, the coefficient of variation of the fertilization amount stability, and the coefficient of variation of the fertilization amount consistency in the same row as evaluation indices. Simulations and comparative tests of FA performance were performed for three cases of the busbar top-to-bottom curvature variation: (i) gradual increase (GI), (ii) gradual decline (GD), and (iii) zero (0) variation. The experimental results show that at the FA rotation speed of 100~120 r/min and tilt of 1°~5°, the optimized FA had the optimal performance. High tilts and low rotation speeds provided the worst performance, with the variation coefficient of inter-row fertilization amount consistency of the FA below 10.23%. The variation coefficient of fertilizing amount stability was lower than 6.74%. The variation coefficient of intra-row fertilizing amount consistency was lower than 3.52%, while all performance indicators met the quality requirements of fertilizer discharge. Bench tests of the FA revealed that the variation coefficient of inter-row fertilizing amount consistency of the FA was below 10.23%, the variation coefficient of fertilizing amount stability was below 6.74%, and the variation coefficient of intra-row fertilizing amount consistency was below 3.52%. Field tests of the FA revealed that the variation coefficient of inter-row fertilizing amount consistency was below 7.68%, the variation coefficient of fertilizing amount stability was below 4.95%, and the variation coefficient of intra-row fertilizing amount stability was below 3.57%. All parameters were better than the industry standard, demonstrating that the FA had good fertilizing performance and met the quality requirements of field fertilization operations.

РАЗРАБОТКА ЦЕНТРОБЕЖНОГО РАБОЧЕГО ОРГАНА РАЗБРАСЫВАТЕЛЯ МИНЕРАЛЬНЫХ УДОБРЕНИЙ

In variable-rate application of solid mineral fertilizers (SMF), working units of centrifugal fertilizer distributors can regulate precisely the application rate and evenly distribute pellets over the fi eld. To determine the most rational parameters and modes of a solid fertilizer distributor, infl uencing the fl ight path of pellets and the uniformity of their distribution over the fi eld, the authors carried out theoretical and experimental research of a centrifugal disc of a solid fertilizer distributor equipped with a rotary acceleration chamber and a set of exchangeable U-shaped blades. The authors describe the infl uence of the blade length on the trajectory and the fl ight distance of the fertilizer pellets as well as the infl uence of the rotation of the dispersal chamber outlet window on the fertilizer distribution pattern. The experiment on determining aerodynamic properties of the nitroammonium phosphate pellets (60:60:60) was carried out using the developed laboratory bench of the solid fertilizer distributor. The experiment allowed determining the physical parameters of pellets infl uencing the range and trajectory of their fl ight - the winglet ratio and the critical speed. It was found that the rotation displacement of the dispersal chamber outlet window of the spreading disc leads to the displacement of the intensive coverage zone in the direction of the window rotation. This makes it possible to regulate the intensity and has a direct impact on the distribution zone of solid mineral fertilizers. The paper justifi es the most rational design of the spreading disc. The research proved that the greatest uniformity of solid mineral fertilizer spreading is observed when using a disk with eight paired coaxially located blades with a length of 300, 250, 200, and 100 mm.

DEM simulation model to optimise shutter hole position of a centrifugal fertiliser distributor for precise application

The purpose of this study is to analyse the distribution pattern of centrifugal fertiliser distributor with two shutter holes and obtain the optimal position of the shutter holes for improved distribution uniformity. A simulation model of the centrifugal fertiliser distributor was generated by discrete element method (DEM). The behaviour of fertiliser particles on the spinner was analysed by the simulation and the simulation model was verified through a stationary distribution pattern test. The distributor design was modified using the verified simulation model to improve the distribution uniformity. The simulation results of the existing fertiliser distributor showed the amount of fertiliser applied on the right side of the machine was 1.59 times higher than the amount applied on the left (R/L ratio) and the coefficient of variation (CV) was 34.88% at stationary condition indicated non-uniform fertiliser distribution. As the position of the shutter holes was moved in the direction of rotation of the spinner (i.e. clockwise) the amount of fertiliser distributed towards the right side decreased. The shutter hole position accordingly adjusted to improve fertiliser distribution uniformity. When the optimal position of the shutter hole was used under stationary condition, the R/L ratio was close to 1.0, whilst the CV value decreased by approximately 50%. The optimal solution was also suitable during continuous application when applying at a width of 8 m since CV values were

Разработка лабораторного стенда для исследования рабочих органов распределителей удобрений центробежного типа

Разработка лабораторного стенда для исследования рабочих органов распределителей удобрений центробежного типа

Ресурсосберегающий метод оценки качества работы центробежных разбрасывателей минеральных удобрений

Ресурсосберегающий метод оценки качества работы центробежных разбрасывателей минеральных удобрений

Interaction of the bar-plate conveyor of the machine with mineral fertilizers

Annotation Purpose. Determining the impact and interaction of the bar-plate conveyor with the mass of fertilizers to justify the choice of its parameters and mode of operation, ensuring the stability of the process. Methods. Theoretical calculations, their analysis. Results. The structural scheme of the process of mineral fertilizers leakage by bar-plate conveyor through the unloading window is substantiated. The effectiveness of fertilizers largely depends on the correct combination of methods of their introduction into the soil. There are two ways to use fertilizers: continuous surface sifting and internal soil application. Depending on the terms and norms perform basic and pre-sowing application, as well as fertilization [1]. Centrifugal mineral fertilizer spreaders, which use disks with the possibility of making the working mixture on the surface at an angle to the horizon have become widespread. This is due primarily to the versatility of the tool, in which due to the reorientation of the disk you can get high quality fertilizers and achieve high widths of spread. Conclusions. The results of the kinematic analysis showed that the theoretically possible uneven distribution of mineral fertilizers can reach 34–60%, in fact it is less due to the elasticity and shedding of fertilizers. To reduce the uneven distribution in the design of the machine, we have provided an intermediate hopper with an inclined auger, due to which we were able to significantly reduce the intermittent supply of mass by the conveyor. Secondly, due to the auger, we have achieved the versatility of the machine: after removing the centrifugal working body, the machine can be used for other work. Keywords: mineral fertilizers, bar-plate conveyor, spreading and local fertilization.

Development of a Stereovision-Based Technique to Measure the Spread Patterns of Granular Fertilizer Spreaders.

Centrifugal fertilizer spreaders are by far the most commonly used granular fertilizer spreader type in Europe. Their spread pattern however is error-prone, potentially leading to an undesired distribution of particles in the field and losses out of the field, which is often caused by poor calibration of the spreader for the specific fertilizer used. Due to the large environmental impact of fertilizer use, it is important to optimize the spreading process and minimize these errors. Spreader calibrations can be performed by using collection trays to determine the (field) spread pattern, but this is very time-consuming and expensive for the farmer and hence not common practice. Therefore, we developed an innovative multi-camera system to predict the spread pattern in a fast and accurate way, independent of the spreader configuration. Using high-speed stereovision, ejection parameters of particles leaving the spreader vanes were determined relative to a coordinate system associated with the spreader. The landing positions and subsequent spread patterns were determined using a ballistic model incorporating the effect of tractor motion and wind. Experiments were conducted with a commercial spreader and showed a high repeatability. The results were transformed to one spatial dimension to enable comparison with transverse spread patterns determined in the field and showed similar results.

Теоретичне дослідження відцентрового розкидача мінеральних добрив

Теоретичне дослідження відцентрового розкидача мінеральних добрив

Application of the image processing technique in identifying the particle dispersion from a centrifugal fertilizer spreader

ABSTRACTParticle dispersion in the vicinity of an agricultural fertilizer spreader is difficult to capture due to the rapid particle traveling motion. This paper introduced a granule impact indentation-based technique to simultaneously record the two-dimensional particle dispersion from a spinning concave disc type of spreader. A Nitrogen-Phosphorus-Potassium (NPK) type of fertilizer was utilized to induce indentations on aluminum foils placed on the wall panels confining an experimental spreader system. Subsequently, an image processing technique which is comprised of the multicolor edge detection, the curve closing, and the region merging techniques was purposely developed to automatically identify and locate the granule impacts on the sampled foil digital images. Overlapping impacts were characterized based on the granulometry of the fertilizer sample. The reconstructed particle dispersion pattern using the image processing method showed good agreement with the experimental observations. The outcome of this research enabled a fast and effective method for quantitatively assessing the particle distribution for a specific fertilizer spreader.

High speed stereovision setup for position and motion estimation of fertilizer particles leaving a centrifugal spreader.

A 3D imaging technique using a high speed binocular stereovision system was developed in combination with corresponding image processing algorithms for accurate determination of the parameters of particles leaving the spinning disks of centrifugal fertilizer spreaders. Validation of the stereo-matching algorithm using a virtual 3D stereovision simulator indicated an error of less than 2 pixels for 90% of the particles. The setup was validated using the cylindrical spread pattern of an experimental spreader. A 2D correlation coefficient of 90% and a Relative Error of 27% was found between the experimental results and the (simulated) spread pattern obtained with the developed setup. In combination with a ballistic flight model, the developed image acquisition and processing algorithms can enable fast determination and evaluation of the spread pattern which can be used as a tool for spreader design and precise machine calibration.

DEVELOPMENT OF A PRECISION FARMING SYSTEM FOR TURKISH FARMERS

The objective of this paper is to explain the information about a precision farming system which has been developed for Turkish farmers. The developed system includes a variable rate controller for centrifugal fertiliser spreaders, an application map software and an autonomous steering system for tractors. The variable rate controller for the centrifugal fertiliser includes stepper motors used to adjust the distributed fertiliser amount. An electronic control system was designed to control stepper motors in addition to a DGPS system, which was used to determine positioning. The application map software was used to provide communication between the variable rate system and the stepper motor, computer and DGPS. In order to develop a variable rate controller, a toothed axle was fitted to the stepper motor. A variable rate controller was developed to combine cereal sowing machines. This system includes step motors for each seed metering unit as well as PIC, PDA and GPS receivers. The software was developed to create an application map and send signals to control units. Furthermore, an automated steering system was developed by a private Turkish company. Preliminary test results of this system were successful. The system is still being tested.

Estimation of two-dimensional fertiliser mass flow distributions by recording granule impacts

A new method to simultaneously measure the horizontal and vertical distributions of the mass flow in the vicinity of the spinning disc of a centrifugal fertiliser spreader is presented. The method records granule impacts on a cylindrical vertical screen placed around the disc. The screen is covered with a paper band, a carbon film and a protective coat, so that granules hitting the screen produce impact marks on the recording paper band. A mathematical model is used to estimate the local impact density by correcting the bias due to overlapping impacts. Algorithms were developed to process the recording band, taking into account its location with respect to the spreading device. The distribution of the mass flow is studied for two fertilisers. The findings demonstrate that processing impact record clearly characterises the horizontal and vertical distributions of the mass flow for a compound fertiliser NPK and potassium chloride. For the horizontal distribution, comparisons are carried out with results deduced from a traditional compartmented ring. This new approach paves the way for the design of alternative tests and diagnostic tools to characterise centrifugal fertiliser spreading. • Fertiliser distribution is measured around a spinning disc by recording impacts. • Distributions are obtained simultaneously in horizontal and vertical directions. • An impact-overlapping model is used to correct the distribution estimation. • Impact records clearly distinguish the mechanical behaviour of NPK and KCl. • Results are compared with those derived from a compartmented ring method.

Application of a 3-D laser scanner for characterising centrifugal fertiliser spreaders

The suitability of using 3-D laser technology to assess the performance of a twin disc centrifugal fertiliser spreader was analysed. A static test with an Amazone ZA-M twin disc fertiliser spreader distributing di-ammonium sulphate was developed. The spreader was adjusted to spread the fertiliser at a distance of 12 m at three different rates. The test was conducted inside a building; 64 sample boxes were installed on the floor within a 2 m × 2 m frame. Considering the static test, for each spreading rate, five consecutive measurements were made using a Leica HDS6000 3D laser scanner. The information supplied by the laser scanner was correlated with the weight of the fertiliser collected in the boxes using linear regression equations. Each regression model was obtained for one particular and specific spreading configuration. This reduces the applicability of the method because for each spreader setting requires a new surface distribution to be measured to establish a new regression model. A field test was conducted to obtain a fertiliser distribution curve, with the machine set at 41.1 kg min −1 , while the tractor was progressing at 8 km h −1 . This information was used to validate the laser technology by comparing the real distribution curve with the simulated curve. The correlation coefficient (adjusted R 2 ) was 0.86. The information provided by the scanner also enabled the surface distribution of the product, the maximum spreading distance, the spreading symmetry on both sides of the machine and the trajectory of the grains of fertiliser to be analysed.

Discrete element method modelling of a centrifugal fertiliser spreader

Experimental testing and calibration of new machines and fertiliser can be costly and time consuming. Standard centrifugal fertiliser spreaders are designed to achieve a uniform distribution across the entire field. Fruit trees, however, are planted in rows and it would be advantageous to concentrate the fertiliser closer to the tree trunk and hence the root system. This could reduce the amount of fertiliser needed and will also reduce the negative environmental impact. A discrete element method (DEM) model of a centrifugal fertiliser spreader was developed. A sensitivity study was used to determine the DEM parameters by comparing the results to experimental results. The effects of the disc speed, feed position, feed rate and vane angle on the spread pattern were investigated experimentally and compared to the DEM results. A deflector plate was designed to separate the flow into two paths along the tree lines. The DEM results of the deflector were compared to the experimental results. It was shown that the DEM model can be used to make both qualitative and quantitative predictions of the spread pattern under different spreader settings. The model could also accurately predict the effect of the deflector on the spread pattern. This indicates that DEM can be a powerful tool in the development of new spreader concepts.

Measurement of an equivalent friction coefficient to characterise the behaviour of fertilisers in the context of centrifugal spreading

In the context of centrifugal fertiliser spreading, numerous mechanical models demonstrate that the acceleration on the spinning disc depends on the friction coefficient of the fertiliser against the vane. Nevertheless, when the dynamic friction coefficient is measured by traditional methods, the values obtained do not reflect fertiliser behaviour differences. The study proposes a new estimation of the friction coefficient termed “equivalent friction coefficient” (EFC). This parameter is deduced from a mechanical model of the fertiliser motion on a spinning disc and from the measurement of the outlet angle of the particles. The outlet angle is measured using a simple imaging system that captures a high number of particle trajectories in the vicinity of the spinning disc in a few seconds. Values obtained for three common fertilisers are compared. For a flat disc rotating at 800 rpm and equipped with radial vanes, the EFC values are, respectively, 0.13, 0.14 and 0.44 for ammonium nitrate, NPK and KCl. The influence of disc configuration, vane profile and rotational speed is addressed. The influence of fertiliser moisture content is also investigated. Results demonstrate that this method can be used to obtain a relative classification of fertilisers. This paves the way for the definition of a normalized method, which will classify fertilisers in terms of real spreading behaviour.

Recent results of experimentation and DEM modeling of centrifugal fertilizer spreading

For the past few decades there has been a growing concern about the environmental implications associated with the use of soil fertilizers. In Europe, over 90% of fertilizer is distributed using spinning disc spreaders. The popularity of spinning disc spreaders lies with their relative low cost. However, the performance of these machines is highly dependent on the particle properties (e.g. friction coefficients, shape). This results in large differences in spread patterns depending on the fertilizer type as well as the prevailing weather conditions (e.g. air humidity). This dependence requires extensive experimental calibration of the spreader for each type of fertilizer. When a new spreader is designed this calibration work has to be largely repeated. DEM is believed to be the key to increase the understanding of the spreading process, the design of better spreaders and a drastic reduction of experimental calibration. The paper reviews recent results in experimentation and modelling of an international research consortium running several industrial research projects on centrifugal fertilizer projects.

Estimation of the in‐field variation in fertiliser application

Variation in field application from a centrifugal fertiliser spreader has, in the past, been difficult to assess due to the intensive field testing required. However, with the application of current technologies such as Global Positioning Systems and Geographic Information Systems, the assessment of field application variation is now possible. The aim of this research was to develop a method to assess field application variation using basic transverse spread pattern test and vehicle tracking data. The information was used to measure and compare the effect of spread pattern, driving accuracy, driving method and paddock shape. Two differently shaped paddocks were used for analysis, one rectangular, the other triangular. A simple analysis method was initially used to calculate which areas of the paddock received nil, single, or double application. An advanced assessment method was also developed to measure application variation within the paddock and to calculate field application variation. Transverse spread pattern data was averaged at 2 m increments and linked to GPS tracking data from the spreading vehicle using ArcGIS 9.1©. The dataset was then analysed and a field application map produced. The field coefficient of variation (CV) was then calculated from the application map. Three simulations of perfect driving width and perfect application pattern were also conducted as a means of comparison to the actual field data. Simple analysis results showed, in both paddocks, the area receiving the correct application rate was between 70 and 80%, with 5–15% of the area receiving nil application. Using the advanced analysis method, the calculated field CV was 32.9 and 43.0% for the triangular and rectangular paddocks, respectively. However, when simulated “perfect driving” tracking data were used, the average field CV was reduced to 24.8 and 23.5%, respectively. When both perfect driving and a perfect spread pattern were used field application variation could be reduced to less than 20% for either shaped paddock. The results concluded that there is far greater variation in field application of fertiliser than that measured from a single transverse test, with the single biggest gain in calculated field CV being from driver accuracy and driving method.

A discrete element model for simulation of a spinning disc fertilizer spreader I. Single particle simulations

Modeling approaches for centrifugal fertilizer spreaders have so far been based on analytical expressions for single particle trajectories derived in the early 60's. However elegant this approach was, it suffers from several disadvantages, the most important of which is failing to incorporate the interaction between the particles in the flow. This paper is the first in a series aiming at simulating the complete spreading process based on the laws of physics and a physically meaningful model for the interactions between the particles, c.q. the contact forces. The result is a model that allows the development of a deeper understanding of the physics underlying the spreading process and provides better predictions. In this paper the model is presented in detail and a series of simple computer experiments are analysed and compared to theoretical predictions. Also, single particle trajectories from DEM simulations are compared to experimental results. Further, some effects of the model parameters are analysed. This paper demonstrates that the model is not only capable of producing realistic simulations, but also provides detailed insight in the physics of the spreading process.

Model for Simulation of Particle Flow on a Centrifugal Fertiliser Spreader

An analysis of the motion of a particle on a rotating flat disc is conducted and a basic equation of motion derived for a single particle. The analysis is directly applied to the flow of particles on a centrifugal fertiliser spreader. Equations of motion are derived for flat disc/radial vanes type of spreaders and further generalised for the more common conical disc/pitched vanes type. The derived equations of motion form part of the basis of a simulation model for centrifugal (or spinning disc) fertiliser spreaders with the equations of motion through the air completing the model. In the simulation, the collective flow of particles is treated as a superposition of single-particle trajectories with different initial conditions. The spreader model is applicable for the development of spreader control systems for site-specific fertiliser application as well as for the design and optimisation of spreaders.